The iButton® 64Kb memory (DS1996) is a rugged read/write data carrier that acts as a localized database that can be easily accessed with minimal hardware. The nonvolatile memory offers a simple solution to storing and retrieving vital information pertaining to the object to which the iButton device is attached. Data is transferred serially via the 1-Wire® protocol which requires only a single data lead and a ground return. The scratchpad is an additional page that acts as a buffer when writing to memory. Data is first written to the scratchpad where it can be read back. After the data has been verified, a copy scratchpad command will transfer the data to memory. This process ensures data integrity when modifying the memory. A 48-bit serial number is factory lasered into each DS1996 to provide a guaranteed unique identity which allows for absolute traceability. The durable MicroCan package is highly resistant to environmental hazards such as dirt, moisture, and shock. Its compact button-shaped profile is self-aligning with mating receptacles, allowing the DS1996 to be easily used by human operators. Accessories permit the DS1996 to be mounted on almost any surface including plastic key fobs, photo-ID badges and printed circuit boards. Applications include access control, work-in-progress tracking, electronic travelers, storage of calibration constants, and debit tokens.